The present invention relates to control valves, and more particularly to a valve operator for manually operating a control valve.
Flow control valves, including plug valves, are used in a number of different applications. Some guiding principles in designing and implementing control valves include the desire to employ a simple and efficient valve and operator having a relatively low number of parts, with the assembled valve being cost effective, efficient, and reliable in operation.
Current implementations of control valves often utilize an automated actuator to actuate the control valve. The automated actuator can have a pneumatic or electric source of power.
The possibility of the control valve actuator failing at some point during its lifetime varies with each control valve. Because the possibility exists, it is desirable in many instances to provide a manual backup valve operator, or an auxiliary valve operator, to duplicate the function of the automated valve actuator during a failure. The valve operator can also be used in instances where the automated valve actuator is properly functioning, and for other reasons (such as manual override), it is desirable to have the ability to open and close a control valve without using the actuator.
There is a need in the art for a valve operator having a fewer number of parts, a relatively low manufacturing cost, and a high operating efficiency relative to known valve operators in use today. The present invention is directed toward further solutions to address this need.
In accordance with one example embodiment of the present invention, a valve operator includes a rotatable spindle extending along an axis. The rotatable spindle is rotatable about the axis. The rotatable spindle is additionally pivotable about a first pivot point. A pivotable linkage operably couples with the spindle. The pivotable linkage is pivotably movable about a second pivot point, such that rotation of the spindle about the axis moves the pivotable linkage in a pivoting motion about the second pivot point. Rotation of the spindle can additionally pivotally move the spindle about the first pivot point.
The valve operator can be mounted in combination with an automated valve actuator on the same control valve. The automated valve actuator can have a number of different power sources, including pneumatic and electronic.
In accordance with one aspect of the present invention, a bearing forms the first pivot point. A reaction force from the pivotable linkage can push a first end of the spindle against the bearing. A structure fixed to a yoke of an actuator coupled to the valve operator supports the bearing.
According to another aspect of the present invention, a support bracket for supporting the pivotable linkage is fixed to a yoke of the actuator. The support bracket includes a first bracket arm and a second bracket arm. Each of the first and second bracket arms can extend to the second pivot point from the yoke of the actuator.
In accordance with further embodiments of the present invention, the pivotable linkage generally forms about a 90xc2x0 angle between each of first and second ends and the pivot point. Alternatively, the pivotable linkage can form greater than or less than about a 90xc2x0 angle between each of first and second ends and the second pivot point.
In accordance with still another aspect of the present invention, a pivot pin extending through a pivot bore within the pivotable linkage forms the second pivot point. In addition, a threaded fixture operably coupling the rotatable spindle with the pivotable linkage mounts within a bore of a first end of the pivotable linkage. A bearing mounted within the bore supports the threaded fixture. The threaded fixture can take the form of a nut, in addition to other structures.
In accordance with still further aspects of the present invention, the threaded fixture rotatably mounts in a manner enabling the rotation of the threaded fixture about a rotation axis perpendicular to the axis of the threaded spindle and parallel to a rotation axis of the second pivot point. This arrangement allows the threaded fixture to be pivotable about the first pivot point, wherein the first pivot point is distal from the threaded fixture.
In accordance with still another aspect of the present invention, a second end of the pivotable linkage extends to couple with a stem. The stem can be an actuator stem or a valve stem. The actuator stem and valve stem can likewise couple together.
In accordance with still another aspect of the present invention, a rounded tip is disposed at a first end of the threaded spindle. The rounded tip facilitates the pivoting and rotating movements of the threaded spindle.
In accordance with still another aspect of the present invention, a wheel is disposed at a second end of the threaded spindle for actuating a rotation force on the threaded spindle.
In accordance with yet another embodiment of the present invention, a pivotable lock nut is disposed to receive the threaded spindle. The lock nut is disposed to lock the threaded spindle to prevent rotation.
In accordance with still another embodiment of the present invention, a valve operator is provided having a rotatable threaded spindle. The spindle extends along an axis and is rotatable thereabout. The spindle is pivotable about a first pivot point. A pivotable linkage having a first end, a second end, and a second pivot point is also provided. A bore extends at least partially through the first end of the linkage. A threaded fixture rotatably mounts at the bore for receiving the threaded spindle. The threaded fixture is rotatable about an axis parallel to an axis of the second pivot point. The second end of the pivotable linkage couples to a stem, such that rotation of the spindle causes the linkage to pivot about the second pivot point to effect movement of the stem.
In accordance with another embodiment of the present invention, a system is provided for actuating a valve. The system includes an automated valve actuator. In addition, a valve operator is provided. The valve operator includes a rotatable spindle having a first end, a second end, and a center line axis extending therebetween. The first end rotatably couples to a bearing and the spindle is pivotable about a first pivot point at the bearing. A pivotable linkage having a first end, a second end, and second pivot point therebetween, is also provided. The first end supports a rotatable threaded fixture that receives the rotatable spindle, and the second end extends to communicate with a stem.
The present invention provides a side mounted valve operator. The assembly of the valve operator can be configured so that the pivotable linkage in one mode can push a valve stem downward, and in another mode the assembly can be inverted so the operator pushes a valve stem upward. No additional parts are required between each of the two modes.
Furthermore, the present invention provides for a mechanism using manually induced motion and lifting forces applied to valve and actuator stems at a greatly increased mechanical efficiency over known art, and using a reduced number of bearings. Known manual valve operators have at least one additional bearing within the operator mechanism relative to the operator of the present invention.